1. Field of the Invention
The present invention relates to a motor driven column apparatus, and more particularly, to a unique motor type motor driven column apparatus using one unified motor to implement tilt and telescoping motions.
2. Description of Related Art
In general, motor driven power steering (MDPS) systems which are motor driven steering systems are a type which does not use fluid pressure and assists steering power with motor power, and are mainly applied to compact vehicles.
An MDPS system has a decelerator including a worm shaft and a worm wheel rotating by a motor in order to assist the steering power, and uses a motor driven column apparatus having a tilt motor and a telescoping motor to implement tilt and telescoping motions, respectively.
An MDPS motor is controlled by an MDPS ECU, and the tilt motor and the telescoping motor are controlled by a separate tilt/telescoping ECU.
As importance of improvement of fuel efficiency of vehicles is emphasized, there is a trend in that the MDPS systems should be necessarily applied to not only compact vehicles but also mid-size and full-size vehicles.
FIG. 8 shows a motor driven column apparatus having an MDPS motor, a tilt motor, a telescoping motor, and an MDPS ECU and a tilt/telescoping ECU for controlling those motors as described above.
As shown in FIG. 8, the motor driven column apparatus has an MDPS motor 200 and a decelerator for assisting steering power provided in a column tube 100 covering a steering shaft 100a, a tilt mechanism for tilting column tube 100 up and down, and a telescoping mechanism for telescoping transmission.
The tilt mechanism includes a tilt motor 300 which is a power source, a deceleration gear 301 decelerating the rotation of the motor and increasing torque, and a tilt rod 302 moving a tilt bracket 303 by an output of deceleration gear 301.
The telescoping mechanism includes a telescoping motor 400 which is a power source, a deceleration gear 401 decelerating the rotation of the motor and increasing torque, and a telescoping rod 402 moving a telescoping bracket 403 by an output of deceleration gear 401.
Also, an MDPS ECU 210 for controlling MDPS motor 200 and a tilt/telescoping ECU 500 for controlling tilt motor 300 and telescoping motor 400 are provided, respectively. MDPS ECU 210 is configured to receive a signal of an MDPS motor/angle sensor, and tilt/telescoping ECU 500 is configured to receive signals of a tilt motor/angle sensor and a telescoping motor/angle sensor.
However, since the tilt mechanism having MDPS motor 200 for assisting the steering power and the tilt mechanism having tilt motor 300 and the telescoping mechanism having telescoping motor 400 are separately provided to the motor driven column apparatus as described above, a structure for tilt and telescoping operations is complex, and especially, when the motor driven column apparatus is installed together with a knee airbag, a column collision absorption structure, etc., it is very difficult to secure a package.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.